The present invention relates to apparatus for transporting rod-shaped articles which constitute or form part of smokers' products. More particularly, the invention relates to improvements in apparatus for manipulating so-called chargers or trays which contain arrays of parallel plain or filter tipped cigarettes, cigars, cigarillos or cheroots, or arrays of parallel filter rod sections. Still more particularly, the invention relates to improvements in apparatus for delivering filled trays to and for removing empty trays from magazines of processing machines for rod-shaped articles which constitute or form part of smokers' products.
It is already known to insert filled trays into carriers which are thereupon inverted so as to allow the contents of filled trays to descend by gravity, e.g., into the magazine of a packing or other processing machine. In many instances, the carriers are disposed in pairs so that one thereof can store a filled tray and the other thereof can dispense the contents of a filled tray. The carriers are mounted on a common holder and are caused to move between a first station where the carriers are relieved of empty trays and receive filled trays and a second station where the contents of filled trays are dumped into the magazine of a consuming or processing machine, e.g., into the magazine of a packing machine.
Presently known chargers or trays are normally open at the front side and at the top so that they can be loaded by introducing rod-shaped articles through the front side and that, upon inversion, their contents can be evacuated through the open tops. The articles which leave an inverted tray by gravity descend onto the supply of articles which are already contained in the magazine of the processing machine (hereinafter called packer for short). The distance which the descending articles leaving the inverted tray should cover is relatively short; otherwise, the articles are likely to lose tobacco particles, to undergo deformation and/or to lie askew in the interior of the magazine. This can entail lengthy interruptions in the operation of a packer which is supposed to process many thousands of articles per minute, i.e., each and every (even very short) interruption of normal operation of the packer can entail enormous losses in output. For example, one or more filter plugs or filter cigarettes which lie askew are likely to interfere with proper descent of similar articles in the magazine, to interfere with proper evacuation of articles through the outlet of the magazine, to cause damage to and/or deformation of adjacent articles and/or other malfunctions and/or defects.
One of the solutions which are resorted to in presently known apparatus for transferring the contents of filled trays into the magazines of packers or the like is that the inverted tray is deposited immediately on top of the magazine, so that the distance between the lowermost layer or stratum of articles in the inverted tray and the uppermost layer or stratum of articles in the magazine is relatively short. Such solution is quite satisfactory if an empty tray can be lifted off the magazine within a short interval of time, so that the inlet of the magazine is immediately exposed for reception of articles through the inverted open top of a filled container. In the absence of such mode of operation, the level of articles in the magazine descends very rapidly during removal of an emptied tray and during subsequent placing of an inverted filled tray on top of the magazine. Therefore, when the filled tray comes to rest on the magazine and begins to discharge its contents by gravity, the articles which leave the tray must cover a considerable distance with the aforediscussed detrimental effect or effects. Therefore, the rate at which the packer processes the articles must be reduced in order to avoid misalignment of articles which descend from the interior of the inverted tray. In other words, the mechanism which transports filled trays to and removes empty trays from the magazine of a packer constitutes a bottleneck in the production line which normally includes one or more cigarette makers, one or more filter tipping machines, one or more filter rod making machines and one or more packers. As a rule, the carriers for trays are mounted on their holders for pivotal movement about horizontal or nearly horizontal axes. Therefore, any pivotal movement of a carrier which contains a freshly emptied tray must be preceded by at least some upward movement of such carrier in order to enable the freshly emptied tray to share the pivotal movement of its carrier without striking against the top of the magazine. The same holds true for the delivery of a filled tray; such tray must be pivoted with its carrier about a horizontal axis prior to slight or even pronounced downward movement to come to rest on top of the magazine in a packer or the like.
Certain types of presently known apparatus for the transport of filled and empty trays are disclosed, for example, in U.S. Pat. No. 3,655,080 to Gianese; in U.S. Pat. No. 4,056,206 to Bennett and in German Offenlegungsschrift No. 2,018,442. The patent to Gianese discloses an apparatus wherein a filled tray is lifted by an elevator to be introduced into a carrier which is thereupon inverted to place the tray therein on top of a magazine. The empty tray is extracted from the carrier and is delivered to a removing conveyor for transport to a discharge area. The patent to Bennett discloses two carriers which must be lifted prior to deposition of a full tray (in inverted condition) on top of a magazine. The German publication discloses an apparatus wherein the inverting device for filled trays occupies a relatively small space, as considered radially of the axis of rotation of the inverting device. This is achieved by appropriate selection of the positions of carriers for empty and filled trays with reference to the axis of rotation of the carriers. The German publication stresses the reduction in the mass of parts to be inverted; such reduction is attributed to greater compactness of the apparatus.